I have kind of stopped modding the Aveo and therefore the mid brace never was improved on. My thought is to strip a section of undercoating off the car, weld some peices of flat stock to it for where the bolts will go, thread it and build some better braces. Once done, I can put bolts in the threaded holes to protect the threads, spray with undercoating then install the braces. With flat black paint, they would even look stock.
To get rid of some of the understeer, pick up some 17mm Polyurethane bushings for the front swaybar. This will stiffen the front a little more and actually help reduce understeer.